HAYWARD — A woman has been charged with felony counts of assault and elder abuse in an attack on 73-year-old R&amp;B singer Lester Chambers of Petaluma at a Northern California blues festival where he had just dedicated a song to Trayvon Martin.

The San Francisco Chronicle reported Wednesday (bit.ly/15FRm91) that Alameda County prosecutors charged 43-year-old Dinalynn Andrews-Potter of Barstow in the July 13 attack at the Hayward festival.

Authorities say Chambers was performing the song "People Get Ready" for Florida teen Martin just after George Zimmerman was acquitted of second-degree murder when Andrews-Potter shouted something and shoved the singer into an amplifier. Chambers ended up on the ground with bruises and swelling.

Chambers and his family had asked that Andrews-Potter be charged with a hate crime, but authorities say her motives were unclear.

Andrews-Potter told police she had a stress disorder and a repetitive part of the song caused her to snap. It wasn't clear if she had an attorney.